Down's syndrome, also known as Down syndrome, is a genetic condition that typically causes some level of learning disability and characteristic physical features.

Around 775 babies are born with the condition each year in England and Wales.

Many babies born with Down's syndrome are diagnosed with the condition after birth and are likely to have:

• reduced muscle tone leading to floppiness (hypotonia)
• eyes that slant upwards and outwards
• a small mouth with a protruding tongue
• a flat back of the head
• a below average weight and length at birth

Although children with Down's syndrome share some common physical characteristics, they do not all look the same. A child with Down's syndrome will look more like their mother, father or other family members than other children with the syndrome.

People with Down's syndrome also vary in personality and ability. Everyone born with Down's syndrome will have a degree of learning disability, but the level of disability will be different for each individual.

Read more about the characteristics of Down's syndrome.

Screening for Down's syndrome

In some cases, babies with the condition are identified before birth as a result of screening for Down's syndrome.

Screening tests can't tell you for definite if your baby has Down's syndrome, but they can tell you how likely it is. If screening suggests there is a chance your baby does have Down's syndrome, further tests can be carried out during pregnancy to confirm it.

If testing indicates your child will be born with Down's syndrome, you should be offered genetic counselling to allow you and your partner to discuss the impact of the diagnosis.

You may also be offered an appointment to meet a doctor or other health professional who works with children with Down’s syndrome, who can also tell you more about the condition and answer any questions you may have.

Read more about diagnosing Down's syndrome.

What causes Down's syndrome?

Down's syndrome is caused by the presence of an extra copy of chromosome 21 in a baby's cells.

In the vast majority of cases, this isn't inherited, and is simply the result of a one-off genetic mistake in the sperm or egg.

There is a small chance of having a child with Down's syndrome with every pregnancy, but the risk increases with the age of the mother. For example, a woman who is 20 has about a one in 1,500 chance of having a baby with the condition, while a woman who is 40 has a one in 100 chance.

There is no evidence that anything done before or during pregnancy increases or decreases the risk of having a child with Down's syndrome.

Read more about the causes of Down's syndrome.

Life with Down's syndrome

Although there is no "cure" for Down's syndrome, there are ways to help children with the condition develop into healthy and fulfilled individuals who are able to achieve a level of independence right for them. This includes:

• access to good healthcare, including a range of different specialists
• early intervention programmes to provide support for children and parents
• good parenting skills and an ordinary family life
• education and support groups to provide information and help for parents, friends and families

Improved education and support has led to more opportunities for people with Down's syndrome. These include being able to leave home, form new relationships, gain employment and lead largely independent lives.

However, it is important to remember that each child is different and it is not possible to predict how individuals will develop.

Read more about living with Down's syndrome.

Associated health conditions

There are a number of disorders that are more common in people with the condition. These include:

• hearing and vision problems
• heart disorders, such as congenital heart disease
• thyroid problems, such as an underactive thyroid gland (hypothyroidism)
• recurrent infections, such as pneumonia

Your child may be checked by a paediatrician more often than other children to pick up developing problems as early as possible. If you have any concerns about your child's health, discuss them with your GP, health visitor or paediatrician.

Read more about the complications of Down's syndrome.

Down's Syndrome Association

If you would like more information about Down's syndrome, you can visit the Down's Syndrome Association or call their helpline on 0333 121 2300.